summaryrefslogtreecommitdiff
path: root/utils/mmap-windows.c
diff options
context:
space:
mode:
authorMike Frysinger <vapier@gentoo.org>2009-02-10 00:09:04 +0000
committerMike Frysinger <vapier@gentoo.org>2009-02-10 00:09:04 +0000
commit0d5aec1211d900a532a66830d814cd5358c96b3a (patch)
treedf5c35e13e55f5dc457b9bc4b1ca0e71d71ab43c /utils/mmap-windows.c
parente0da861a29f864f1646603ae62e336fda093477c (diff)
add mmap()/munmap() implementation for Windows
Diffstat (limited to 'utils/mmap-windows.c')
-rw-r--r--utils/mmap-windows.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/utils/mmap-windows.c b/utils/mmap-windows.c
new file mode 100644
index 000000000..1799392f0
--- /dev/null
+++ b/utils/mmap-windows.c
@@ -0,0 +1,100 @@
+/* mmap() replacement for Windows
+ *
+ * Author: Mike Frysinger <vapier@gentoo.org>
+ * Placed into the public domain
+ */
+
+/* References:
+ * CreateFileMapping: http://msdn.microsoft.com/en-us/library/aa366537(VS.85).aspx
+ * CloseHandle: http://msdn.microsoft.com/en-us/library/ms724211(VS.85).aspx
+ * MapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366761(VS.85).aspx
+ * UnmapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366882(VS.85).aspx
+ */
+
+#include <io.h>
+#include <windows.h>
+#include <sys/types.h>
+
+#define PROT_READ 0x1
+#define PROT_WRITE 0x2
+/* This flag is only available in WinXP+ */
+#ifdef FILE_MAP_EXECUTE
+#define PROT_EXEC 0x4
+#else
+#define PROT_EXEC 0x0
+#define FILE_MAP_EXECUTE 0
+#endif
+
+#define MAP_SHARED 0x01
+#define MAP_PRIVATE 0x02
+#define MAP_ANONYMOUS 0x20
+#define MAP_ANON MAP_ANONYMOUS
+#define MAP_FAILED ((void *) -1)
+
+#ifdef __USE_FILE_OFFSET64
+# define DWORD_HI(x) (x >> 32)
+# define DWORD_LO(x) ((x) & 0xffffffff)
+#else
+# define DWORD_HI(x) (0)
+# define DWORD_LO(x) (x)
+#endif
+
+static void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
+{
+ if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))
+ return MAP_FAILED;
+ if (fd == -1) {
+ if (!(flags & MAP_ANON) || offset)
+ return MAP_FAILED;
+ } else if (flags & MAP_ANON)
+ return MAP_FAILED;
+
+ DWORD flProtect;
+ if (prot & PROT_WRITE) {
+ if (prot & PROT_EXEC)
+ flProtect = PAGE_EXECUTE_READWRITE;
+ else
+ flProtect = PAGE_READWRITE;
+ } else if (prot & PROT_EXEC) {
+ if (prot & PROT_READ)
+ flProtect = PAGE_EXECUTE_READ;
+ else if (prot & PROT_EXEC)
+ flProtect = PAGE_EXECUTE;
+ } else
+ flProtect = PAGE_READONLY;
+
+ off_t end = length + offset;
+ HANDLE mmap_fd, h;
+ if (fd == -1)
+ mmap_fd = INVALID_HANDLE_VALUE;
+ else
+ mmap_fd = (HANDLE)_get_osfhandle(fd);
+ h = CreateFileMapping(mmap_fd, NULL, flProtect, DWORD_HI(end), DWORD_LO(end), NULL);
+ if (h == NULL)
+ return MAP_FAILED;
+
+ DWORD dwDesiredAccess;
+ if (prot & PROT_WRITE)
+ dwDesiredAccess = FILE_MAP_WRITE;
+ else
+ dwDesiredAccess = FILE_MAP_READ;
+ if (prot & PROT_EXEC)
+ dwDesiredAccess |= FILE_MAP_EXECUTE;
+ if (flags & MAP_PRIVATE)
+ dwDesiredAccess |= FILE_MAP_COPY;
+ void *ret = MapViewOfFile(h, dwDesiredAccess, DWORD_HI(offset), DWORD_LO(offset), length);
+ if (ret == NULL) {
+ CloseHandle(h);
+ ret = MAP_FAILED;
+ }
+ return ret;
+}
+
+static void munmap(void *addr, size_t length)
+{
+ UnmapViewOfFile(addr);
+ /* ruh-ro, we leaked handle from CreateFileMapping() ... */
+}
+
+#undef DWORD_HI
+#undef DWORD_LO